The only thing that ever really frightened me during the war was the U-boat peril," wrote Winston Churchill in his monumental history of World War Two. In many ways, the Atlantic shipping lanes, where U-boats preyed on American ships, were the true front of the war. England depended on the United States for nearly all of its supplies, most of which were transported across the Atlantic by boat. These shipping lanes thus became the main target of German naval operations between 1940 and 1945, accounting for the fact that the casualty rate was higher here than in any other theater of the entire war. Though often overlooked, the Battle of the Atlantic was crucial to both sides. Had Germany succeeded in cutting off the supply of American ships, England would have likely not held out; the outcome of the war -- as well as the future of Europe and the world -- would have been remarkably different. Jonathan Dimbleby's The Battle of the Atlantic offers a detailed and gripping account of this campaign, using contemporary diaries and letters from leaders and sailors, evoking the lives of those who fought to keep the shipping lanes open. He also places the fighting in the context of the entire Second World War, delving into both the politics on both sides of the Atlantic. Among other things, Dimbleby reveals the role of Bletchley Park, and the complex and dynamic relationship between America and England, producing the definitive narrative treatment of the longest battle of World War Two.